biostudies-literatureKarakus ISAustrian Science Fund FWFMarmara ÜniversitesiMarmara University94https://www.ebi.ac.uk/biostudies/studies/S-EPMC10997552biostudies-literatureUnknown44(4)<h4>Purpose</h4>Deficiency of stromal interaction molecule 1 (STIM1) results in combined immunodeficiency accompanied by extra-immunological findings like enamel defects and myopathy. We here studied a patient with a STIM1 loss-of-function mutation who presented with severe lymphoproliferation. We sought to explore the efficacy of the mTOR inhibitor rapamycin in controlling disease manifestations and reversing aberrant T-cell subsets and functions, which has never been used previously in this disorder.<h4>Methods</h4>Clinical findings of the patient were collected over time. We performed immunological evaluations before and after initiation of rapamycin treatment, including detailed lymphocyte subset analyses, alterations in frequencies of circulating T follicular helper (cT_FH) Journal of clinical immunologyRapamycin Controls Lymphoproliferation and Reverses T-Cell Responses in a Patient with a Novel STIM1 Loss-of-Function Deletion.PMC10997552ADT-2022-10661Lise Meitner fellowshipOzen AYorgun Altunbas MBal SKKarakoc-Aydiner ECaki-Kilic SBaris SBabayeva RBoztug KYalcin Gungoren EZemheri IEFrohne ACatak MCKarakus ISEltan SBBayram Catak FKraakman MJEsen FfalseRapamycin Controls Lymphoproliferation and Reverses T-Cell Responses in a Patient with a Novel STIM1 Loss-of-Function Deletion.<h4>Purpose</h4>Deficiency of stromal interaction molecule 1 (STIM1) results in combined immunodeficiency accompanied by extra-immunological findings like enamel defects and myopathy. We here studied a patient with a STIM1 loss-of-function mutation who presented with severe lymphoproliferation. We sought to explore the efficacy of the mTOR inhibitor rapamycin in controlling disease manifestations and reversing aberrant T-cell subsets and functions, which has never been used previously in this disorder.<h4>Methods</h4>Clinical findings of the patient were collected over time. We performed immunological evaluations before and after initiation of rapamycin treatment, including detailed lymphocyte subset analyses, alterations in frequencies of circulating T follicular helper (cT_FH) 2024-01-01T00:00:00Z2024 Apr2025-04-04T12:47:50.267Z2025-04-04T12:47:50.267ZS-EPMC109975523857856910.1007/s10875-024-01682-0